Fractionation Of Spent Coffee Ground With Tertiary Amine Extraction

Spent coffee ground (SCG) was fractionated with a tertiary amine (N,N dimethylcyclohexylamine, CyNMe2) to obtain a carbohydrate fraction rich in dietary fiber, a phenolic fraction made of chlorogenic acids (CGAs), and a lipid fraction mainly consisted of palmitic and linoleic acid. The extraction time (6-24 h) and temperature (25-45 degrees C) were evaluated at a constant solvent-to-sample ratio (12:1, v/w). The carbohydrate fraction obtained with CyNMe2 showed relative high values of total dietary fiber (63 to 83%). The highest concentration of phenolic compounds was obtained after 24 h at 25 degrees C. Seven major species of chlorogenic acids were detected within the phenolic fraction, ranging from 1.83 to 7.16 mg g(-1) of dry matter. The lipid fraction obtained with CyNMe2 was overestimated by 186% (13.91 +/- 2.3 g 100 g(-1)) over the Soxhlet extraction (7.48 g 100 g(-1)) due to an incomplete conversion of the amine into its respective salt.